TaskManager: Fix for showing column selection menu on right click on the task manager list.

chrome/browser/resources/task_manager/main.js

Index: chrome/browser/resources/task_manager/main.js
diff --git a/chrome/browser/resources/task_manager/main.js b/chrome/browser/resources/task_manager/main.js
index d2089b31e2695aa7a2a42ca921748db06dfda0b9..94c1cbe8aff596fb055ee54e62f1d12edfd5508e 100644
--- a/chrome/browser/resources/task_manager/main.js
+++ b/chrome/browser/resources/task_manager/main.js
@@ -265,6 +265,9 @@ TaskManager.prototype = {
     cr.ui.contextMenuHandler.addContextMenuProperty(this.table_.header);
     this.table_.header.contextMenu = this.columnSelectContextMenu_;
 
+    cr.ui.contextMenuHandler.addContextMenuProperty(this.table_.list);
+    this.table_.list.contextMenu = this.columnSelectContextMenu_;
+
     this.document_.addEventListener('command', this.onCommand_.bind(this));
     this.document_.addEventListener('canExecute',
                                     this.onCommandCanExecute_.bind(this));